Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful behavioral detail: partial failures degrade gracefully, bundlephobia's first measurement can take 5-30s, and sources_failed will list timeouts while the rest still returns. This goes beyond annotations and sets accurate expectations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Single paragraph is information-dense and front-loaded with the core purpose and use case. It packs in many output field names and caveats, but each clause earns its place for a composite tool; minor lack of structural formatting keeps it from a 5.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, so the description compensates by listing exact summary fields, per-advisory detail, links, alternative versions, and failure behavior. For a complex multi-source read tool with two parameters, this is complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Input schema fully covers both params (package name with scoped support, version defaulting to latest). The description does not add significant new parameter semantics beyond the schema; it mostly restates the default and explains output fields, so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states it is a composite check for deciding whether to add an npm package, aggregating license, advisories, version history, and bundle size from deps.dev and bundlephobia. This specific verb+resource+scope distinguishes it from generic scan tools like scan_competitor_ai_presence.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly tells the agent when to use: 'Use whenever an agent asks...' and gives a clear exclusion for non-NPM ecosystems ('PyPI / Maven / Cargo / Go fall under deps.dev:version directly'), meeting the when/when-not bar.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.